Internal combustion engine and method of operating same.

摘要

The invention relates to an internal combustion engine (21) specifically a two cycle internal combustion engine allowing altering the compression ratio to provide optimum running under all conditions. An arrangement is provided for cleaning the exhaust control valve (47) and its surrounding cooperating surfaces of the engine upon cutting off of the engine to preclude the formations of deposits that can cause sticking of the valve element. The valve element is rotated through a number of cycles after the engine is stopped through a wider range than during its normal valving operation for removing deposits. The number of cycles is chosen in response to an engine condition such as length of time of running or amount of lubricant supplied to the engine. Various valve arrangements are disclosed that improve the cleaning operation and permit cleaning even while the engine is running. <IMAGE>